<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>取得文件修改时间</title>
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-base.css" />
<link media="all" rel="stylesheet" type="text/css" href="styles/03e73060321a0a848018724a6c83de7f-theme-medium.css" />

 </head>
 <body class="docs"><div class="navbar navbar-fixed-top">
  <div class="navbar-inner clearfix">
    <ul class="nav" style="width: 100%">
      <li style="float: left;"><a href="function.fileinode.html">« fileinode</a></li>
      <li style="float: right;"><a href="function.fileowner.html">fileowner »</a></li>
    </ul>
  </div>
</div>
<div id="breadcrumbs" class="clearfix">
  <ul class="breadcrumbs-container">
    <li><a href="index.html">PHP Manual</a></li>
    <li><a href="ref.filesystem.html">文件系统函数</a></li>
    <li>取得文件修改时间</li>
  </ul>
</div>
<div id="layout">
  <div id="layout-content"><div id="function.filemtime" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">filemtime</h1>
  <p class="verinfo">(PHP 4, PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">filemtime</span> &mdash; <span class="dc-title">取得文件修改时间</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.filemtime-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>filemtime</strong></span>(<span class="methodparam"><span class="type">string</span> <code class="parameter">$filename</code></span>): <span class="type"><span class="type">int</span>|<span class="type"><span class="type false">false</span></span></span></div>

  <p class="para rdfs-comment">
   本函数返回文件中的数据块上次被写入的时间，也就是说，文件的内容上次被修改的时间。
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.filemtime-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt>
<code class="parameter">filename</code></dt>

     <dd>

      <p class="para">
       文件的路径。
      </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.filemtime-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
      返回文件上次被修改的时间， 或者在失败时返回 <strong><code>false</code></strong>。时间以 Unix 时间戳的方式返回，可用于
   <span class="function"><a href="function.date.html" class="function">date()</a></span>。
  </p>
 </div>


 <div class="refsect1 errors" id="refsect1-function.filemtime-errors">
  <h3 class="title">错误／异常</h3>
  <p class="para">
失败时抛出 <strong><code>E_WARNING</code></strong> 警告。
</p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.filemtime-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2167">
    <p><strong>示例 #1 <span class="function"><strong>filemtime()</strong></span>  例子</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;outputs&nbsp;e.g.&nbsp;&nbsp;somefile.txt&nbsp;was&nbsp;last&nbsp;modified:&nbsp;December&nbsp;29&nbsp;2002&nbsp;22:16:23.<br /><br /></span><span style="color: #0000BB">$filename&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #DD0000">'somefile.txt'</span><span style="color: #007700">;<br />if&nbsp;(</span><span style="color: #0000BB">file_exists</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"</span><span style="color: #0000BB">$filename</span><span style="color: #DD0000">&nbsp;was&nbsp;last&nbsp;modified:&nbsp;"&nbsp;</span><span style="color: #007700">.&nbsp;</span><span style="color: #0000BB">date&nbsp;</span><span style="color: #007700">(</span><span style="color: #DD0000">"F&nbsp;d&nbsp;Y&nbsp;H:i:s."</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">filemtime</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">));<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

   </div>
  </p>
 </div>


 <div class="refsect1 notes" id="refsect1-function.filemtime-notes">
  <h3 class="title">注释</h3>
  <blockquote class="note"><p><strong class="note">注意</strong>: <p class="para">注意：不同文件系统对时间的判断方法可能是不相同的。</p></p></blockquote>
  <blockquote class="note"><p><strong class="note">注意</strong>: <span class="simpara">此函数的结果会被缓存。参见
<span class="function"><a href="function.clearstatcache.html" class="function">clearstatcache()</a></span> 以获得更多细节。</span></p></blockquote>
  <div class="tip"><strong class="tip">小技巧</strong><p class="simpara">自 PHP 5.0.0 起, 此函数也用于<em class="emphasis">某些</em>
URL 包装器。请参见 <a href="wrappers.html" class="xref">支持的协议和封装协议</a>以获得支持 <span class="function"><a href="function.stat.html" class="function">stat()</a></span> 系列函数功能的包装器列表。</p></div>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.filemtime-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.filectime.html" class="function" rel="rdfs-seeAlso">filectime()</a> - 取得文件的 inode 修改时间</span></li>
    <li class="member"><span class="function"><a href="function.stat.html" class="function" rel="rdfs-seeAlso">stat()</a> - 给出文件的信息</span></li>
    <li class="member"><span class="function"><a href="function.touch.html" class="function" rel="rdfs-seeAlso">touch()</a> - 设定文件的访问和修改时间</span></li>
    <li class="member"><span class="function"><a href="function.getlastmod.html" class="function" rel="rdfs-seeAlso">getlastmod()</a> - 获取页面最后修改的时间</span></li>
   </ul>
  </p>
 </div>

</div></div></div></body></html>